This invention relates to methods and apparatus for winding armatures and for connecting the related armature coil leads to the commutator of the armature.
A primary object of the invention is to provide methods and apparatus for winding armatures without the need for wire winding guides used in prior art machines to guide the wire delivered by a flyer into the slots of the armature stack. By eliminating such wire guides, numerous advantages can be obtained. These advantages include eliminating costly machining processes required for producing the wire guides. Another advantage consists in avoiding the tensile fatigue which the wire undergoes using the winding guides. In conventional winding, this occurs because the wire being delivered by the flyer hits surfaces and/or edges of the winding guides each time the wire is drawn to run into the slots of the armature stack.
The invention also allows for the elimination of the traditional tooling required for carrying out lead connections to the commutator. Such tooling typically includes an outer commutator shield for avoiding the possibility that the wire being wound may catch on the commutator during winding of armatures having tang connections. Such tooling also typically includes an inner commutator shield for covering certain commutator tangs while exposing others for lead attachment. Tooling of this type and methods for obtaining tang connections have been described in U.S. Pat. Nos. 3,927,843 and 3,913,220. Another lead attachment tool which can be eliminated is the hooking plate which facilitates attachment of the wire to the tangs of the commutator (see, for example, commonly assigned U.S. patent application Ser. No. 610,928, filed Nov. 9, 1990). Elimination of these lead connection tools reduces machine manufacturing costs, and also provides for a winding machine which can attach leads belonging to different armature types without requiring the usual change-over or set-up of such tools, as is required in conventional winding machines.
The invention can also be used to ensure that the wire does not hit the commutator during winding. In conventional winding operations, the wire delivery point of the flyer has a trajectory which would cause the wire to catch on the commutator at periodic intervals. To avoid this, conventional machines are provided with the previously mentioned outer shield for covering the commutator. Even so, the wire hits the outer shield, which causes the wire being wound to be subjected to tensile fatigue. The present invention makes it possible to keep the wire entirely clear of the commutator during the winding operation, thereby avoiding this problem.
Different armature types have different parameters for purposes of winding. These different parameters include: the number of stack slots for receiving coils, the number of lead attachments to the commutator, the stack length, the stack diameter, the commutator diameter, the commutator length, the distance separating the commutator face from its adjacent stack end face, the winding scheme, and the diameter of the armature shaft (i.e., the diameter of the shaft portions around which the coils are supported). In conventional winding, variations in the above parameters usually require the machine or its various parts to be extensively modified to adapt the flyer winder to wind different armatures. The methods and apparatus of this invention greatly reduce or simplify the adaptations required in order to wind armatures of different types in the same winder.